56. 合并区间(leetcode)

https://leetcode.cn/problems/merge-intervals/?envType=study-plan-v2&envId=top-100-liked

合并区间练习题

typedef pair<int,int> PII;
vector<PII> segs;
class Solution {
public:
    vector<vector<int>> merge(vector<vector<int>>& intervals) {
        segs.clear();
        for(int i=0;i<intervals.size();i++)
        {
            int l=intervals[i][0],r=intervals[i][1];
            segs.push_back({l,r});
        }
        merge(segs);
        vector<vector<int>> res;
        for(int i=0;i<segs.size();i++)
        {
            vector<int> temp;
            temp.clear();
            temp.push_back(segs[i].first);
            temp.push_back(segs[i].second);
            res.push_back(temp);
        }
        return res;
    }


    void merge(vector<PII> &segs)
    {
        vector<PII> res;
        sort(segs.begin(), segs.end());
        int st = -2e9, ed = -2e9;
        for (auto seg : segs)
        if (ed < seg.first)
        {
            if (st != -2e9) res.push_back({st, ed});
            st = seg.first, ed = seg.second;
        }
        else ed = max(ed, seg.second);
        if (st != -2e9) res.push_back({st, ed});
        segs = res;
    }
};